Plants 30–40(–60) cm. Stems 1–3, usually unbranched or occasionally of a single branch. Leaves almost all basal, petiolate, petioles 3–18 cm; blade triangular-ovate in outline, 6–9 × 5–10 cm, ternate-3–4-pinnate, very finely dissected; ultimate segments linear, 1.5–4 × 1–2 mm. Umbels 1.5–2.5 cm across in flower, to 10 cm in fruit; bracts absent; rays (6–)15–30(–40), (2–)3–5 cm; bracteoles 2–4, 0.7–2 mm; umbellules 2–4-flowered; pedicels 0.1–2 mm. Calyx teeth subulate, ca. 1 mm. Petals white, ca. 2 × 1 mm. Stylopodium conic; styles elongate; stylopodium plus style ca. 1 mm. Fruit oblong-ovoid, 3–4 × 0.8–1.2 mm, often only one mericarp develops in fruit; ribs filiform; vittae 1–3 in each furrow, 4 on commissure. Fl. Mar–May, fr. Jun–Aug.